Forging a plate

[Mike Tsayper]

I wonder how long would it take to forge a 2.5 kg billet of iron into a 2 mm thick sheet, with a hand hammer?

Trying to figure out the cost of plate armor before water powered hammers became common..

[Exo313]

Quick Google search seems to indicate that the trip hammer significantly predates full plate armor. History buffs will know more. 

It also depends on what you mean by plate armor. If you're thinking knights in full plate, that's different than say, coats of plate, also called plate armor. 

[Mike Tsayper]

I mean large plates, particularly breastplates. Several kings like Charlemagne and Richard the Lionheart were said to wear iron breastplates, and there's the Philip II's iron armor in one museum in Greece, retrieved from his tomb. These were made before the 13th century when trip hammers began to appear in Europe.

[Steve Sells]

you do know that water hammers have been around for two thousand years or longer?

[Mike Tsayper]

Maybe in China but not in Europe. For Europe there's only one dubious passage about water powered ore crushing by Pliny IIRC

[Kevin Olson]

2 hours ago, Mike Tsayper said:

I wonder how long would it take 

Under 2 hours

[Mike Tsayper]

Thanks

[Steve Sells]

1 hour ago, Mike Tsayper said:

Maybe in China but not in Europe.

funny how you never stated any location, or how many strikers working

[Mike Tsayper]

Sorry for that. But Chinese didn't make [full] plate armor so the Europe was implied. They were the first followed by Japanese several centuries later afaik.

If you could provide an estimate how the total work time diminishes with additional strikers it would be great

[swedefiddle]

Good Morning,

Go ahead, Time yourself. This thought process is a waste of my time. It may have mattered at some point, I don't care now.

Neil

[Exo313]

3 hours ago, Mike Tsayper said:

If you could provide an estimate how the total work time diminishes with additional strikers it would be great

Would that be one or three flint?

I find I always need one more striker than I have because the others have wandered off!

[anvil]

A note of Interest,, at the Potsdam armory during the time if Frederick the Great(1750's), they forged muskets and breastplates, amonst other things.

They forge welded the "swarf" from milling the barrels to make these breastplates for the heavy cav. 

They tested them by firing 2 pistol balls at them. If they went thru they were rejected. 

These two dents were taken as a "proof mark/Maker's Mark" of quality. 

If they did not have these two dents, the cav wouldn't accept them.

[Frosty]

Welcome aboard Mike, glad to have you. If you'll put your general location in the header you might be surprised how many IFI members live within visiting distance.

Is there a point to your question? If you really want to know you're going to need to dig into some of the old blacksmith guild records in Europe. They kept close records of this type thing so they could set "proper" prices and wages. 

Telling us a factor of your question is "implied" simply means YOU think we know what you're thinking. Power hammering iron plate most certainly wasn't only an European thing, hammered iron cook pots (for example) were common long before people were drawing wire to make ring maille. 

Tilts were being used in Europe long before iron was in common use, for I believe felting west of the east. In India who knows they were pretty advanced.

Believe me, the first time a smith saw a tilt they began adapting it to hammering copper. By the iron age it was old tech.

Frosty The Lucky.

 

[Irondragon Forge ClayWorks]

Welcome to IFI Mike. As Frosty suggested edit your profile to show your location as a lot of answers depend upon it. Have you read this thread yet?

 

[ThomasPowers]

Earliest water  powered hammer I'm pretty sure about in northern Europe was in the 900's (personal communication at the Medieval Technology Conference held at Penn State.)

Can you cite those folks using plate armour? 14th century is the usual given time where it started with maille and ended with full plate. The usual progression was using more smaller plates, gradually switching to fewer larger plates---until they started to heat treat them and then the number of smaller plates went up till they started getting good at managing the variables and went back to fewer larger plates.  (Some of the research on it will show the number of plates vs the years...)

Got a number of basic issues in your question too; like "a hand hammer": having only one person hammering in the smithy is rather like having only 1 person in a formula 1 pit crew.  How long does it take a single person pit crew to change the tires in a formula one race??? The master smith wouldn't be hammering out a block into sheet---that's grunt work! (I get a lot of "how long did it take a blacksmith to forge a sword?"---same sort of things: it was a team job and the smith only did the blade, grinding/polishing was a different guild as was engraving as was hilting as was scabbards,...the cutler often took the orders and subcontracted the work out to the various workers...)

Also we're talking about real wrought iron as mild steel didn't come around until the 1840's/50's With the Bessemer/Kelly process.  Real wrought iron is much softer under the hammer as it's forged at much higher temperatures.

May I seriously commend to your attention "The Knight and the Blast Furnace" Alan Williams as the preeminent modern work on the metallurgy of plate armour.

Also "The Royal Armoury at Greenwich, 1515-1649 : a history of its technology"   WILLIAMS, Alan ; REUCK, Anthony de ;

(they sent their metal out to a "batter mill" to be made into sheet.

Also remember that medieval armour was not uniform in thickness a single piece might vary in thickness by 50% with impact zones being thicker than covered edges.

(Beware a lot of the 19th and early 20 century research; it's been shown to be pretty bogus...go for the late 20th and early 21st century stuff!)

HOWEVER your original question has a big flaw as you are basing the cost on the time; not on the skill and specialized equipment.  Leonardo Da Vinci is going to charge a lot more to painting a meter sq painting than a house painter!.  There is a lot of research out there already dealing with the cost of arms and armour; some even taking into account inflation. (An interesting measure was "How many cows did it cost?")

[Rashelle]

Another consideration I think is being forgotten is the realization that that 2.5kg billet is not going to be 2.5kg anymore once it's forged out.

[ThomasPowers]

(and real wrought iron will probably lose more as some of the ferrous silicates will get pushed out as well as scale losses.  I wonder if he's taking into account they were forging with charcoal...)

[Mike Tsayper]

I'm sorry for not specifying my answer enough but there's so little info in the google (i have tortured it for several weeks but with very little success) i thought i won't get any answers if my question was too narrow 

On early plate armor:

Quote

One likely example is the "plate of worked iron" described by Guillaume le Breton and worn by Richard of Poitou (later King Richard I of England) under his hauberk during his joust with William de Barres. There are also a couple of surviving examples of iron plate armour dating back to the Hellenistic period. The most famous is attributed to Philip of Macedon, the father of Alexander the Great. The cuirass was made of wrought iron and trimmed with gold.

http://myarmoury.com/feature_mail.html

Quote

Charlemagne's biographer Notker describes the formidable appearance of Charlemagne and his army at the siege of Pavia (774), in full battle gear:
    That man of iron [was) topped with his iron helmet, his fists in iron gloves, his iron chest and his broad shoulders clad in an iron cuirass. An iron spear raised on high against the sky was gripped in his left hand. In his right he held his still unconquered sword . .. [His thighs) were bound in plates of iron . . . his greaves [lower-leg coverings] too were made of iron. His shield was all iron. His horse itself gleamed iron in color and in mettle. All those who rode before him, those who accompanied him on either flank, those who followed, wore the same armor, and their gear was as close a copy of his own as it is possible to imagine . . . The rays of the sun were reflected by this battleline of iron. This race of men harder than iron did homage to the very hardness of iron.

CATHEDRAL, FORGE, AND WATERWHEEL by Frances & Joseph Gies

 

During the high medieval times, some "one-piece" helmets were made (e.g. norman helmets, king Wenceslas' helmet) weighing about 2-3 pounds. So making a sizeable plate was not beyond the means of blacksmiths of those days, though most of the early helmets were made of several small plates riveted together (spangenhelm). Romans also were making solid iron helmets during the early imperial period (1-2 centuries A.D.) until they got back to bronze helmets (and iron mail for body protection, back from lorica segmentata).

ThomasPowers, I have scoured through "The Knight and the Blast Furnace" but didn't find what i need. Thanks for the second reference, will look there.

The weight and thickness info i have obtained from several sources. Breastplates were typically 2-4 kg, about 2 mm average thickness, more in the center, less on the edges.

I understand there could be a lot of different factors affecting the price. I don't insist the time to make iron into a sheet was the key factor in the cost of pate armor, i was just guessing if it was so. Now i don't think it was (as it could be done just for 1-2 manhours of unskilled labor). Maybe the forging of the bloom was, though that does not seem likely too..

I've found in "The Knight and the Blast Furnace" the author estimates a 10 kg billet was needed to make a 2.5-4.5 kg plate (so the total time should be increased 2-4x times? or less as the forging melts away and it remains less to hammer). He also writes there's no trace of fold-forging so these large ignots should have been made from a single bloom. But the amount of loss in both phases (bloom to billet, billet to sheet) should depend on the speed of work a lot...

[ThomasPowers]

You do realize that the best sources for this information generally ARE NOT ON THE NET!  What academic journals are you subscribed to? Searching thesis submissions, etc 

Have you corresponded with Ric Furrer?   (Perhaps even asking on the Arch Metals mailing list.)   I hope you are aware of the forge welding of real wrought iron to bring in more mass. (IIRC Ric used that method to bulk up material he used in NOVA's "Secrets of the Shining Knight"

Bloom will need to be extensively worked to get usable armour making materials. Plate Armour was a high end item in the earlier times and the time used by highly skilled armoursmiths was  the biggest cost.  BTW do you have "Heroic Armor of the Italian Renaissance" on the Negrolis?

(I had the remains of 3 teeth pulled Saturday and am not in good shape to do a library crawl!) I assume that you have already found sources like:

http://medieval.ucdavis.edu/120D/Money.html  (note the cost of a set of armourer's tools!)

 

[MC Hammer]

Great information Thomas!  I learned a lot just reading your posts on this thread and I'm not even interested in armor a whole lot.  

[hanzosbm]

On 7/29/2018 at 4:02 PM, ThomasPowers said:

Also we're talking about real wrought iron as mild steel didn't come around until the 1840's/50's With the Bessemer/Kelly process.  Real wrought iron is much softer under the hammer as it's forged at much higher temperatures.

Hi Thomas, could you clarify this a bit?  Personally, when I hear wrought iron, I think of very low amounts of carbon (like, less than .1%).  Obviously, Europeans were working with much higher carbon content ferrous metals (what I could call steel) during the middle ages and before.  So, I'm thinking that there is more to the term 'wrought iron' than I am aware of and I'd like to get my nomenclature right.

[ThomasPowers]

Wrought iron is a composite material consisting of generally a clean iron matrix with ferrous silicate spicules in it---may have over 100000 per sq inch on the finer grades.

Yes you can have wrought iron derived steels, (like blister and shear steels) or even higher carbon blooms---a bloomery can produce pretty much anything from cast iron to almost carbon free metal; but highC WI's  are rare in the recent scrap stream.

As wrought iron needs to be forged above the melting point of the ferrous silicates to prevent fraying *and* does not burn at the relatively lower temps of modern steels it is often worked at a yellow to white heat where it's as soft as pudding!

Can you explain what needs clarification if this does not cover it?

May I commend to your attention: "Wrought Iron, Its Manufacture, Characteristics, and Applications",  James Aston and "Steel Making Before Bessemer: v. 1: Blister Steel - The Birth of an Industry", Barraclough, Kenneth C.

[hanzosbm]

Thank you very much!  I think I understand now.  So, besides simply the carbon content, it sounds like one of the defining aspects of wrought iron are the silicates, which, if I'm understanding correctly, would essentially be considered an impurity by today's steel standards.  And, because of those silicates, the behavior and therefore methods of working wrought iron is different.  

Assuming that I've understood it correctly (albeit on a very novice level), I appreciate that!

[ThomasPowers]

Yes and it is a composite as it's not just silicon in the alloy but discrete spicules of ferrous silicates---think of it as being like fiberglass with the iron being the resin and the spicules being the glass fibers. Real wrought iron has some neat characteristics and some not so neat ones. It is also what the blacksmith generally worked with for several thousand years. The Bessemer/Kelly process heralded the start of changing to mild steel.  And in the west the crucible steel process is a late process developed by Huntsman in the 1700's during the search for a method to determine longitude.  (It was know centuries earlier in places like Central Asia---Merv for instance where they used it both for crucible steel and for wootz.)

Wrought iron is mainly sourced through the scrap stream these days  and few smiths use it extensively save for those doing high end historical replication and those using it for it's "character" for things like knife fittings.